MICROTEST Transformer Tester 5266

• Test Frequency: 10Hz-500kHz
• 20 Channels
• Built-in Meter Mode
• Simultaneously display four parameters
• Basic accuracy up to ±0.1%
• Open circuit/short circuit function
• RS-232、Handler、LAN、USB Host 、Handler
• Pneumatic fixture F5620 built-in 100mA DC Bias
• USB Host storages can storage setting files, data and capture the screen

Detect capacitance to make sure the insulation between winding position and winding coil is enough

• The winding coil on the transformer include distributed capacitance, it usually distribute between winding coil.
• Capacitance is usually represented by the capacitance by one winding to another winding in an equivalent circuit.
• Cs and Cp is an equivalent capacitance in series or parallel in equivalent circuit.
• D value is the ratio with AC resistance and capacitance, The lower the D value, is better.

Test leakage by LCR balance bridge
When the instrument connect a primary coil with the transformer and the secondary coil is under open status, the test result L= Lp on primary coil + Leakage Current.

→The leakage inside the instrument must short the secondary coil in the transformer.
A ideal secondary coil’s voltage will be 0V in short status. The voltage on both side of primary coil will be 0V. The inductance from primary coil will be the real leakage current.

Offer 100mA DC Bias Current to fulfill Netcom transformer product.

The purpose of detect DC bias is to make sure the specification of coil winding and magnetic saturation.

• _The way we detect is put DC signal on AC signal. The DC signal will cause DC bias on inductance of the transformer. It might also cause magnetic saturation on transformer.
• _Increase inductance by high magnetic conductivity and decrease the turns to minimize the size and raise the efficiency for inductance magnetic coil transformer. Because of the restriction of the permeability material, magnetic flux can’t be unlimited increasing. When it reach the limited, no matter increase the turns or current, the magnetic flux won’t increase. Meanwhile, it will meet the magnetic saturation especially under DC current. The AC current will not cause any change in magnetic flux. The transformer will loose the inductance feature.

The harm of magnetic saturation

• _The magnetic saturated transformer will overheat under low voltage and cause damage by time.
• _It may cause explosion under high voltage.
• _The inductance of primary winding will obliviously decrease on saturated transformer. Meanwhile, the power consumption on DCR and inner MOSEFT will increase rapidly. This may cause the damage on MOSEFT.